Preoperative Medical Clearance: What Internists Evaluate

Preoperative medical clearance is an internist's evaluation of how safely you can go through a planned surgery, and what can be done beforehand to lower the risk. It covers your heart and lung health, chronic conditions, medications and supplements, and any tests that will actually change the plan. The goal is not a stamp of approval but a clear, coordinated plan for the surgeon and anesthesiologist.

"Clearance" is a slightly misleading word. No physician can guarantee a complication-free surgery. What we can do is identify risks early, optimize what is optimizable, and communicate clearly with the surgical team.

What Preoperative Medical Clearance Involves

A good preoperative evaluation answers three questions:

1. What is the risk of this specific procedure for this specific person?
2. Is anything correctable before surgery that would reduce that risk?
3. What should the surgical and anesthesia teams know, and how should medications be managed?

The answers depend on both the patient and the procedure. Cataract surgery carries very different risk from a hip replacement or abdominal surgery.

The Core Elements of the Evaluation

History and functional capacity

I review heart disease, lung disease, diabetes, kidney and liver disease, bleeding or clotting problems, prior reactions to anesthesia, and family history of anesthesia complications.

Functional capacity is one of the most useful parts of the history. Being able to climb a couple of flights of stairs or walk briskly uphill without symptoms suggests reasonable cardiopulmonary reserve. Current guidelines, including the 2024 AHA/ACC perioperative guideline, use functional capacity and validated risk tools to decide whether further cardiac testing is warranted.

Physical examination

Blood pressure, heart and lung examination, airway features relevant to anesthesia, signs of fluid overload, and a general assessment of frailty and nutrition.

Targeted testing, not routine testing

Testing is ordered when the result would change management:

• ECG for people with known heart disease or significant risk factors having higher-risk surgery
• CBC when blood loss is expected or anemia is suspected
• Metabolic panel for people with kidney disease, diabetes, or medications that affect electrolytes
• HbA1c for people with diabetes or suspected diabetes
• Coagulation tests when there is a bleeding history or anticoagulant use
• Pregnancy test when relevant

Routine "everything" panels for healthy people having low-risk surgery rarely help and can lead to delays from incidental findings.

Medication and Supplement Review

This is where many preventable problems hide, and where an internist adds real value. I review every prescription, over-the-counter product, supplement and compounded medication. Read more in medication interaction screening: a hidden danger.

Blood thinners and antiplatelet drugs

Whether and when to pause anticoagulants or antiplatelet medications depends on why you take them and the bleeding risk of the surgery. These decisions should be coordinated with the prescribing cardiologist or specialist and the surgeon. Never stop them on your own, especially after a recent stent.

Diabetes medications

• SGLT2 inhibitors (such as empagliflozin or dapagliflozin) are generally held for several days before surgery because of a risk of ketoacidosis; the labeled timing varies by drug.
• Insulin doses are often adjusted the night before and the morning of surgery.
• GLP-1 receptor agonists such as semaglutide and tirzepatide slow stomach emptying, which raises concern about aspiration under anesthesia. A 2024 multi-society guidance supports an individualized approach: many patients continue, with a liquid diet the day before, while those with significant gastrointestinal symptoms or recent dose escalation may need a different plan. For background, see GLP-1 medications and longevity.

Blood pressure medications

Most are continued. Some, such as certain ACE inhibitors and ARBs, are sometimes held the morning of surgery depending on the anesthesia team's preference.

Supplements, peptides and compounded products

Fish oil, vitamin E, ginkgo, garlic and turmeric can affect bleeding. St. John's wort interacts with many drugs. Compounded hormones, growth hormone secretagogues and investigational peptides may affect blood sugar, fluid balance, blood pressure and healing.

For people on many medications, surgery can be a good moment to simplify. See polypharmacy in aging adults: deprescribing strategies.

Conditions Worth Optimizing Before Surgery

• Uncontrolled blood pressure or diabetes
• Anemia, which may respond to iron or treatment of its cause
• Obstructive sleep apnea, which affects anesthesia and post-operative breathing; patients who use CPAP should bring it
• Active lung disease, such as poorly controlled asthma or COPD
• Smoking: quitting even a few weeks before surgery helps healing and lung function
• Nutrition and frailty, especially in older adults

How to Prepare for Your Visit

• Schedule two to four weeks before surgery.
• Bring a complete list of medications and supplements, or the bottles themselves.
• Bring recent labs, ECGs, echocardiograms and specialist notes.
• Know the exact procedure, date, surgeon and type of anesthesia planned.
• Note any prior problems with anesthesia in you or your family.

At Laeeq M.D., I send a clear written assessment to the surgical team, outlining risks, recommendations and medication instructions, so everyone works from the same plan. You can learn more about our internal medicine services.

Sources

• 2024 AHA/ACC Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: Key Points — American College of Cardiology, 2024. https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2024/09/23/04/15/2024-aha-acc-perioperative-guideline-gl
• New Multi-society Clinical Practice Guidance Released (perioperative use of GLP-1 receptor agonists) — American Society of Anesthesiologists, 2024. https://asahq.org/about-asa/newsroom/news-releases/2024/10/new-multi-society-glp-1-guidance

Book a Consultation

If you have surgery coming up and want a thorough, coordinated preoperative evaluation, plan it a few weeks ahead. You can book a consultation with Dr. Laeeq for a 60-minute visit, in person in Reston, VA or virtually where appropriate.

This article is for educational purposes and is not medical advice. Discuss any treatment with a licensed physician who knows your history.